Gun



Dec. 6, 1938. W. H CHAMBERS l 2,139,648

GUN

Filed Dec. 24, 1956 2 sheets-Sheet 1 l 5 4 7153/0545@ l .3a

Hill lil 21E W. H. CHAMBERS GUN 2 Sheets-Sheet 2.

Filed Deo. 24. 1956 yfwy @afm/MLM wm Patentes Dec. 6, 193s I GUN WalterH. Chambers, Stoneham, Mass.

Application December 24, 1936, Serial No. 117,438

11 Claims.

My present invention relates to guns, more particularly to breechclosures and breech mechanism therefor, and aims to provide simplifiedand otherwise improved means aifording and maintaining a strong,eiicient and uniform closure action with avoidance of inaccuraciescommonly resulting from variations with respect to the so-calledheadspace between the ring chamber or barrel and the closure element.While especially concerned with such mechanism as pertaining to irearmsand small arms, including particularly rifles, whether hand-operated,semi-automatic or full-automatic, in its broader aspects the inventionis applicable in connection with guns in general.

In the drawings illustrating by way of example one embodiment of theinvention,

Fig. 1 is a longitudinal vertical section through the breech andreceiver of a rifle in accordance with one form of the invention;

Fig. 2 is an expanded view showing the receiver and the rear portion ofthe barrel in side elevation and a locking element in Vertical section;

Figs. 3 and 4 are side elevational views of the bolt and lock operatingelement, respectively in the unlocked and the locked positions;

Figs. 5 and 6 are horizontal sections in the plane of the barrel axis,the bolt appearing in closed but non-locked position in Fig. 5 and inlocked position in Fig. 6;

Figs. 7 and 8 are partially diagrammatic views, Fig. 7 representing thelocking element, the lock operating element and the bolt as whenunlocked and Fig. 8 showing said parts in the same position butsuperposed, as viewed from the rear;

Figs. 9 and 1G are views similar to Figs. 7 and 8 respectively, but withthe parts in their locked position;

Fig. 11 is a rear elevation of the receiver and closure, with theoperating element in locked position; and

Fig. l2 is a horizontal section through the rear portion of thereceiver.

Referring more particularly to the drawings, and first to Figs. l and 2,the invention is there illustrated as embodied in a rie comprising abarrel I having at its rear an elongated, integral portion or extension2 adapted for xed connection with the receiver, which latter isindicated as a whole by the numeral 3. In some instances said rearportion 2 of the barrel may be screwed directly into the sleeve-likefront end 4 of the receiver but in the present example I have shown anintermediate adjustable and replaceable bar- (Cl. L12--ll.6)

rel sleeve 5 threaded in xed position on the barrel and itselfexternally threaded for engagement in a like threaded formation at saidfront end i of the receiver.

It will be noted that the rear extension of the barrel, which providesthe actual ring chamber, exten-ds through and rearwardly of saidsleevelike front end ll of the receiver, in their assembled position asin Fig. 1, and into a cylindrical recess in the receiver, herein definedby lower side and bottom wall portions B and a complementary upperportion "I, illustrated as of relatively short rearward extent but whichmay be prolonged rearwardly to any length desired. This recessed portionof the receiver, adjacent the extended rear end of the barrel, isadapted to receive rotatably a rotary locking element or locking sleeveIll. As best seen in Fig. 2, this locking element is internallythreaded, in this instance for reception on the barrel or on the xedsleeve 5 which in effect is an integral portion of the barrel.

As will be understood from the further description this locking elementor collar and its inclined-plane or threaded connections with thebarrel, or with the movable closure element or bolt to be described, areso constructed and arranged as to permit ready turning of the collar onand relatively to the barrel, herein through 90, to bring the breechclosing element or bolt forcibly into intimate locked abutting Contactdirectly with the rear face of the barrel or firing chamber itself,without attendant turning of the head of the bolt, and in such manner asto aiord substantially complete uniformity of head space under alloperating conditions. It will also be understood that while I haveherein illustrated and refer to inclined-plane or threaded formationsbetween the locking element and the barrel, and abutments or lugsbetween said locking element and the bolt, the reverse or .interchangedconstruction may be employed.

Accordingly, in the illustrated embodiment, the locking element IE isformed with interrupted .abutment means comprising angularly spaced andherein oppositely disposed arcuate lugs or anges II, I2 having betweenthem an operating recess or slot I3; see Figs. 'l and 9. In the unlockedposition of the parts, in the present example, said locking lugs, II, I2and operating slot I3 of the locking element I0 stand horizontally, asin Fig. '7, while in the locked position they are vertical, .as in Fig.9. ForWardly of said lugs II, I2 the locking element or collar I0 has anannular recess I5, between the lugs and its threaded portion, forreception of locking lugs on the bolt, in the manner to be described.

The breech closure element proper comprises a bolt or block 20illustrated as an elongated member having oppositely disposed lockinglugs 2l, 22 projecting laterally, herein horizontally, at its front endor head; see particularly Figs. 3, 4, 6 and 7 to 10. The bolt 20 issupported for longitudinal reciprocating movement in the receiver 3 butis held against rotary or turning movement. Hence the lateral lockinglugs 2 I, 22 at the bolt head at all times occupy their substantiallyhorizontal position as in the gures.

Turning of the bolt is prevented in part by said locking lugs 2l, 22,which during opening and closing movement of the bolt ride on longitudinal ways 23, 24 in the receiver, see Fig. 12. It is furtherprevented in the closed position of the bolt as by means of lateral lugs25, 26, Figs. 3, 4 and 11, on an end piece 2'I fitted at the rear of thebolt 2li, secured to it by the screw 28, Figs. 1 and 11. In the closedposition of the bolt said lugs 25, 26 are received in correspondingslots 25a, 26a, Fig. 11, in the enclosing rear portion 3a of thereceiver. The bottom walls of said slots 25a, 245a are in line with andare in effect extensions of the ways 23, 24.

Referring to Fig. 1, said xed but detachable end piece 2l of the bolthas a depending front portion 2'!a which is longitudinally apertured toprovide a bearing for the stem 29 of the firing pin 32 slidably receivedin a longitudinal cylindrical recess 3l in the bolt, herein having itsaxis at a level below the axis of the bore, for cooperation of thefiring pin with cartridges C of the rim-fire type. A shallow recess isformed either in the rear wall of the barrel or ring chamber, or in thefront face of the bolt-at said latter location in the illustratedexampleto receive the head of the cartridge. A firing pin spring 32surrounds and is guided by the stem 29 of the firing pin, bearingbetween the ring pin proper 30 and said depending portion 2'Ia of thebolt end piece 2l.

The nring pin stem 29 carries at its rear end a cocking piece 33 inwhich the stem 29 is threaded and secured as by a nut 34. The receiverhas a longitudinal slot 3b in the rear portion of its bottom wall, forsliding reception 0f said cooking piece. The latter cooperates with asear 35 pivoted as at 35a on the receiver or other fixed part. Suitabletrigger means is provided, herein including a trigger 36 operativelyconnected with the sear as by a pivot 36a and having fulcrurn points 3lengaging the adjacent overlying portion of the receiver. A sear spring38 normally holds the sear elevated, in position to engage in front ofthe cooking piece 33. It will be understood that the ring mechanism asshown and described is merely illustrative, may be widely varied withinthe contemplation of my invention, and may be arranged for single-shotaction as shown, or for semi-automatic or full-automatic action wherethe gun is equipped with a magazine, While the rile as illustrated is ofthe single-loading type, particularly adapted for target work, any knownor preferred magazine and loading mechanism may be supplied.

Referring again to the breech closure elements, and particularly Figs.1, 3 and 4, means is provided for turning the locking element I0, in theforward position of the bolt, to lock the latter in direct engagementwith the rear wall of the barrel, and for unlocking it. Such means maybe variously constructed and arranged. In the illustrated example itcomprises a generally cyi lindrical operating sleeve 4l] rotatablycarried by the bolt. Said sleeve is herein substantially coextensiveWith the bolt and is held in place on it between the bolt rear piece 21and an annular shoulder 4I upon the bolt head.

At the front end of said lock operating sleeve 4U is a pair ofoppositely disposed actuating lugs 43, 44 having projecting portions43a, 44a extending forwardly beyond said shoulder 4I and adapted, in theclosed position of the bolt, to enter the operating slot I3 of thelocking collar I0. Said actuating lugs 43, 44 are similarly shaped andproportioned as the locking lugs 2|, v22 of the bolt and are so locatedthat in one position of the sleeve 4I) relative to the bolt, namely theunlocking position as in Figs. 3, 5, 7 and 8, said lugs on the sleeveand those on the bolt stand in longitudinal alignment substantially incontinuation of each other, and in line with the operating slot I3 ofthe locking collar I3, then in its horizontal or unlocked position. Theoperating sleeve 43 is equipped with a suitable hand lever 45 foreffecting the unlocking and opening, and reverse movements, of the boltand sleeve.

From the foregoing description taken in connection with the drawings,and referring now particularly to Figs. 3, 7 and 8, it will be Vseenthat in the unlocked position of the parts, and throughout thenon-rotating longitudinal movement of the bolt between open and closedpositions, the operating slot I3 of the locking collar I, the actuatinglugs 43, 44 of the operating sleeve ill and the locking lugs 2|, 22 ofthe bolt 2i) all stand in alignment, herein in the horizontal plane, asin said figures. Hence as the bolt and sleeve are moved forwardlytogether, both pairs of lugs will enter the locking collar Iii. Forwardmovement of the bolt and sleeve is terminated by engagement of the boltagainst the barrel. At such time the bolt lugs 2l, 22 are transverselyin line with the annular recess I5 of the locking collar, in advance ofthe collar lugs II, I2, and the front ends 43a, 44a of the sleeve f lugs43, 44 stand in the operating slot I3 between said collar lugs.Accordingly, as the operating sleeve 40 is then turned through 90, byswinging the operating lever 45 downwardly from its position as in Figs.3, 7 and 8 to that of Figs. 4, 9 and 10, it imparts a like rotarymovement to the locking collar I0, moving it from the horizontalposition of its operating slot I3 to the Substantially vertical positionthereof as in Figs. 9 and 10. Since the bolt 2U is prevented fromturning, this rotation of the locking collar I0 brings the lugs II, I2of the latter into locking position behind the lugs 2|, 22 of the bolt.And by reason of the inclined plane or threaded connections between thelocking collar and the barrel, the collar is moved or cammed forwardlywith respect to the barrel and hence, through the describedinterengagement of the lugs of the locking collar and of the bolt, thelatter is forcibly drawn into intimate contact with the rear wall of thebarrel. It will be particularly noted, however, that no relative turningmovement occurs between the bolt and the barrel or between any portionof their mutually contacting surfaces. The hand lever 45, in its down orlocked position of Figs, 4, 9, 10 and 1l is received in a notch 45a inthe adjacent side wall of the rear portion 3a of the receiver. Rearwardmovement of the locked bolt assembly is additionally prevented by theengagement of the squared rear face of the lug 44 of the sleeve 40 in"front of a 'shoulder 3c on the lower wall of the receiver 3, saidshoulder constituting the rear wall of an arcuate recess providing inthe receiver to take said lug 44.

Desirably suitable means is provided for holding the locking element orcollar l in given angular position, particularly while the bolt is open,to insure that the operating slot I3 is properly aligned, hereinhorizontally as in Fig. 7, to receive the bolt lugs 2l, 22 and thesleeve lugs 43, 44 on subsequent closing of the bolt. As best seen inFigs. l and 2 I have herein illustrated for the purpose a ball detent 4lset in a recess in the receiver 3 adjacent the locking collar Il! andurged inwardly toward the latter as by a spring 48 supported on thereceiver as by the screw 49. At the appropriate point on the outer wallof the locking collar is a recess 47a, herein disposed at or near thebottom of said collar when the latter is in its unlocked position, Figs.l and 8. As the collar is rotated into its unlocked position of saidfigures the ball detent 4l snaps into the recess 4la and so yielclablyretains the collar in the desired angular position during the rearwardand return movements of the bolt assembly.

Provision -desirably is made for automatically cocking the ring pin. For-this purpose, referring to Figs. 1, 3 and 4, I have shown the operatingsleeve 40 as formed with a cooking cam 46a for cooperation with a nose33a on the cock-- ing piece 33. In Figs. 3 and 4 the firing pin is seenin cocked position, the elevated position of the Sear 35 being indicatedin dotted line. It will be understood that when the rifle is fired thering pin 3i! and cooking piece 33 move forward, the cocking nose 33a ofthe latter advancing into a recess 48h provided for it in the sleeve 40.In this fired position the cooking nose 33a is adjacent the forwardportion oaf the cam 40a, seen at the bottom of the sleeve 40 in Fig. 4.As the sleeve is rotated from the locked position of Fig. 4 to theunlocked position of Fig. 3, by swinging the operating handle 45upwardly, the cooking piece 33 and the attached firing pin 29, S@ arecammed rearwardly, the nose 33a riding along the edge of the camformation 40a until received in a notch 4ta at the rear thereof. Saidnotch aords an additional safety feature, preventing forward movement ofthe pin until the bolt is closed and the locking sleeve 4G has beenturned toward its position in Fig. 4. It also serves, in cooperationwith the ring pin spring, to retain the mein parts of the bolt assemblyin their proper relative alignment when in unlocked positic-n, andparticularly when said assembly is removed frorn the gun.

The bolt is suitably equipped with an extractor, one form of which isseen in Figs. 4 and 6. As there illustrated it comprises an elongatedspring shank 53 received in a recess intermediate the bolt and thelocking sleeve and carrying at its front end a radially movable hook 54received in a corresponding recess in the rear wall of the barrel orfiring chamber and adapted. to snap over the rim of the cartridge C'.Because of the non-rotary relation between the bolt head and the barrelthe recess in the barrel for the extractor head can be confinedsubstantially to the size oi the latter, thus avoiding the necessityeither for an extended arcuate recess in the barrel or for building theextractor onto the outside of 'the bolt in a manner permitting relativeangular movement between the bolt and extractor. For the same reason,objectionable turning of the extractor relative to and While engagedwith the cartridge is avoided. Any preferred means may be provided forejecting the empty shells upon withdrawal of the bolt.

In the illustrated construction the longitudinal slots 25a, 26a at therear of the receiver for the rear guide lugs 25, 26 of the bolt areproportioned to permit the lugs 43, 44 of the locking sleeve and thelocking lugs 2|, 22 of the bolt to pass rearwardly through said slots,thus `alloW- ing ready removal of the entire bolt assembly as a unit,for cleaning, inspection and replacement purposes. Normally the boltassembly is retained in the receiver by suitable means, which may bevariously constructed and arranged. As best seen in Figs. 2, 11 and 12such means herein comprises a plunger or detent 5S slidable verticallyin a recess in one side wall of the receiver 3. This detent is normallyheld up in bolt-stopping position, as in Fig. 11, by a spring 5l havingslotted connection with the lower end of the detent and xed on thereceiver as by a screw 58. At the inner face the detent is a notch 59 ofthe height of the several lugs of the bolt assembly. The bottom wall orshoulder of said notch stands in the path of the lug 44 of the sleeve,inthe normal elevated position of the detent as in Fig. 1l, thus blockingthe withdrawal of the bolt assembly, it being again noted that said lug44 has a substantially perpendicular rear face. To Withdraw the boltassembly it is necessary merely to.

depress the exposed upper end of the detent 55 so as to bring its notch59 in line with lugs of the sleeve and bolt.

It will be understood that any known or preferred form of stock, grip,sight and other usual parts and accessories for a complete gun or rie,not necessary to illustrate herein, may be provided. The receiver isadapte-d to be secured in the stock by suitable screws, threadedapertures for their reception being indicated in Fig. l in the underportion of the receiver, at both front and rear, as at 3 and 3d.

It will be apparent that the dominant feature of the breech closuremeans of my invention, is the provision for direct locking of thenon-rotated closure or bolt to the Walls of the firing chamber or rearend of the barrel by a third or separately movable element having a camor screw engagement with one of said parts and an abutting engagementwith the other. Said closure means may be arranged for operationotherwise than by a hand-lever such as illustrated, which the operatormoves angularly and longitudinally, and, for example, is readily adaptedfor use With straight-pull, pump, and lever types of actions.

Instead of the removable or adjustable barrel sleeve 5, or in additionto such provision for take-up and adjustment to compensate for possiblewear, means may be supplied for variably limiting the down turningmovement of the bolt handle 45, such as set screw 45b or like verticallyadjustable element at the base of the handle notch 45a in the receiver.As previously noted, the breech mechanism of my invention permits thebolt to be locked at its head, and directly against the rear of thebarrel or ring chamber, without turning of the bolt. Various structuraladvantages in that connection, such as the overcoming of mechanicaldifficulties associated with cartridge extraction common Withhead-locked bolts as heretofore known, have been pointed out in theforegoing description. But of even greater importance isthe fact that inaccordance with the construction and arrangement as herein described andillustrated by way of example there is a resultant uniform locking atthe head of the bolt, and a practical elimination of objectionablehead-space. These several factors all contribute to afford for my gun amaintained accuracy of nre in a remarkable degree and in the presence offull safety of operation.

My invention is not limited to the particular embodiment thereof asillustrated and described herein, and I set forth its scope in myfollowing claims:

1. A bolt assembly for a hand-operated gun comprising an elongatedcylindrical bolt, one or more lateral locking lugs fixed on the bolthead, an operating sleeve rotatably mounted on the bolt, means on thebolt holding the sleeve against longitudinal movement relative thereto,and one or more lateral lugs at the front end of the sleeve, said sleevelugs adapted to aline lengthwise with the bolt lugs in one relativeangular position of the sleeve and bolt.

2. In combination, in a hand-operated gun having a barrel and areceiver, a bolt assembly comprising an elongated cylindrical bolt, oneor more lateral locking lugs Xed on the bolt head, an operating sleeverotatably mounted on the bolt, means on the bolt holding the sleeveagainst longitudinal movement relative thereto, one or more lateral lugsat the front end of the sleeve, said sleeve lugs adapted to alinelengthwise with the bolt lugs in one relative angular position of thesleeve and bolt, and a rotary locking element engageable with the barreland having abutment means adapted for reception behind the locking lugor lugs of the bolt in one angular position of said element, the latterconstructed and arranged for engagement by the lug or lugs of thesleeve, whereby turning of the sleeve effects a like turning of saidelement to lock the bolt at its head to the barrel.

3. In a hand-operated gun, in combination, a receiver, a barrel securedin the front end of the receiver, a recess formation in the frontportion of the receiver, the rear portion of the barrel including itsfiring chamber being extended to project into said recess formation, alocking collar rotatably positioned in said recess and supported on thebarrel, cooperating threaded formations directly engaging each other,one on the barrel and the other on said collar, an abutment lockingformation on the collar and spaced from the rear wall of the barrel, alongitudinally slidable bolt non-rotatably supported in the receiver,the head of said bolt having an abutment locking formation and beingreceivable in the collar with its said locking formation in advance ofthat of the latter, and means for turning the collar to align saidlocking formations thereby to lock the bolt to the barrel.

4. In a gun in accordance with claim 3, the construction wherein themeans for turning the collar comprises a sleeve member rotatable on thebolt and an operating lever connected with said sleeve member.

5. In a manually operated gun, in combination; a receiver; a barrelsecured in the receiver; a bolt mounted for non-rotary reciprocatingmovement in the receiver; a sleeve-like locking element rotatablysupported concentrically by a rear portion of the barrel for directlyinterlocking the barrel and the head of the bolt in the closed positionof the latter, said locking element hav ing interrupted abutment lockingmeans and inclined-plane connecting means; other abutment means andinclined-plane connecting means respectively Acorresponding with thoseof the locking element, one of said second-mentioned means being formeddirectly on the barrel and the other on the fbolt head, whereby rotationof the locking element forcibly locks the bolt head against the rearface of the barrel and directly to said rear portion of the latterthrough said locking element vinterlocking therewith While avoidingrotational movement between the abutting faces of the bolt head andbarrel; and means for turning the locking element.

=6. .In a manually operated gun, a receiver, a barrel secured therein, abolt having non-rotatable vlongitudinal reciprocating movement in thereceiver, a rotary locking element supported on and having directthreaded connection with the barrel and having angularly spaced abutmentmeans disposed circumferentially of the bolt, a locking formation on thebolt head adapted for reception in a transverse plane in advance of saidabutment means when the bolt is closed, and means to turn the lockingelement to bring its abutment means into locking position behind saidhead locking formation of the closed bolt.

7. In a manually operated gun, a receiver, a barrel secured therein, abolt having non-rotatable longitudinal reciprocating movement in thereceiver, a rotary locking element supported on and having directthreaded connection with the barrel and having angularly spaced abutmentmeans disposed circumferentially of the bolt, a locking formation on thebolt head adapted for reception in a transverse plane in advance of saidabutment means when the bolt is closed, means to turn the lockingelement to bring its abutment means into locking position behind saidhead locking formation of the closed bolt, and a spring-pressed detentfor holding the locking element in bolt-,releasing and receivingposition.

8. In a gun having a barrel and a receiver, in combination, alongitudinally slidable bolt, means to prevent rotation of the bolt, arotary locking collar supported on and having direct-threaded engagementwith the barrel and adapted to receive and positively interlock with thefront end or head of the bolt, interengageable abutment formations onthe collar and on the bolt head for effecting said interlockingengagement, means toturn said collar relatively to position saidformations so as to lock and unlock the bolt at its head, and automaticmeans releasable to retain the locking collar in unlocking positionduring retraction and return of the bolt.

9. In a hand-operated gun, in combination, a receiver, a barrel Xed inthe receiver, a bolt slidably and non-rotatably supported in thereceiver, a rotary locking collar upon and having threaded connectiondirectly with a rear portion of the barrel and adapted to receive thehead of the bolt, interengageable circumferentially interruptedabutments on the bolt head and on the locking collar constructed andarranged to align longitudinally in the closed and locked positions ofthe bolt and collar and acting to draw the bolt head non-rotatably intointimate locked contact directly with the rear face of the barrel byturning of the collar on the barrel in one direction and lto release thebolt for rearward opening withdrawal thereof by turning of the collar onthe barrel in the opposite direction, and means for so turning thecollar.

10. In a manually-operated gun, in combination, a receiver having aforward sleeve-like portion and a recessed portion rearwardly thereof, abarrel xed in said forward portion of the receiver and extendingrearwardly into said recessed portion, a bolt mounted in the receiverfor non-rotary longitudinal reciprocating movement and having a headengageable behind the rear end of the barrel to close the firing chambertherein, transverse locking lugs fixed on said head of the bolt, alocking element concentrically surrounding the rear end of the barreland rotatable thereon to locking and unlocking positions, said elementhaving an internal annular recessed portion and spaced abutmentsrearwardly thereof arranged to admit the bolt head and its locking lugsinto said recessed portion, in one angular position of the lockingelement, and to stand behind said bolt head lugs and block rearwardmovement of the bolt in another angular position of the locking element,threaded interlocking connections between the locking element and saidbarrel rear end adapted to advance and retract the locking elementaxially to urge the locked bolt head into uniform closing engagementwith the barrel and its firing chamber, and manual means mechanicallyassociated with the bolt for engaging and turning the locking element.

l1. A bolt assembly for a hand-operated gun comprising an elongatedcylindrical bolt, one or more lateral locking lugs fixed on the bolthead, an operating sleeve rotatably mounted on the bolt, means holdingthe sleeve against longitudinal movement relative to the bolt, one ormore lateral lugs at the front end of the sleeve, said sleeve lugsadapted to aline lengthwise with the bolt lugs in one relative angularposition of the sleeve and bolt, a firing-pin channel eccentricallydisposed in the bolt, and a firing-pin in said channel.

l WALTER H. CHAMBERS.

CERTIFICATE OF CORRECTIONu Patent NoL1 2,159,6h8., December 6, 1958.

WALTER H. CHAMBERS.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page LL,second column, line 52, claim8, for the word "releasable" readreleasably; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 51st day of' January, A. D7 1939,.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.,

